Twitter Interview Tips: Questions Answers & OA Interviews
Twitter/X Interview Prep: Questions & OA Walkthrough
When you join Twitter (now known as X), the hiring journey begins with your resume, which recruiters scrutinize to see if your background, skills, and experience match the requirements of your preferred position!(math.) genusAfter this, you may be presented with your first technical test - an online test (OA). This is mainly to check your programminghard powerand the ability to solve practical problems.
For those of you who successfully passed the OA, congratulations! You will then receive an initial phone call, usually from a recruiter, which is about 15-20 minutes and is more about your culture fit and basic communication skills.
If initial communication goes well.Real technical phone interviewsIt comes, usually one or two rounds. These phone interviews arereal guns and real bulletsThe goal is to look at your technical skills in depth, including programming and problem solving and discussion of various technical issues. The core purpose of the program is to see how well you can work with software fundamentals, handle technical problems, and discuss technical issues on Twitter.Rapidly changing environmentHow did you do.
Telephone Interview PerformanceIt's bright enough.If so, congratulations on your upcoming entry intofinal hurdleAnd alsomost critical,most challengingThe on-site interview session! On-site interviews are usually scheduledvery compact, there are typically four to six rounds that are very comprehensive and will cover programming, system design, and behavioral interviews.
Each round has been carefully designed tofullyEvaluate your technical hard skills and whetherReally fit Twitter's culture. You'll encounter a variety of programming challenges that focus on algorithms and problem-solving ideas, a system design session that looks at your ability to build scalable systems, and a behavioral interview that's more about how you work as a team and how you handle problems when faced with them.
Job Type
front-end engineer
Responsibilities:Build and optimize the web interface directly seen by users to ensure responsiveness, smooth interactions, cross-browser compatibility and accessibility. Handle UI state management and collaborate efficiently with backend APIs to enhance user experience.
Interview technical points: basic DSA (array, string, tree, graph traversal, etc.), system design and front-end scripting languages, scalable UI component libraries, state management solutions (Redux, Zustand, etc.), API communication pattern design, front-end performance optimization (code segmentation, lazy loading, caching strategies, critical rendering paths)
Mobile Engineer
Responsibilities:Develop and maintain native iOS and Android apps for X, implement new features, optimize app performance, memory and power consumption, handle offline scenarios, and integrate device-specific features.
Interviews examine technical points: mobile application architecture design (understanding and application of MVC, MVVM, MVI and other patterns), SDK and API, mobile application life cycle, UI performance optimization (list scrolling smoothness, etc.), memory management, power optimization, multi-threaded programming model, and basic security considerations.
back-end engineer
Responsibilities:Build and maintain server-side services, APIs, message queues, data storage and processing logic that support X's core business. Handle highly concurrent requests, design and implement scalable and highly available distributed systems.
Interviews examine technical points: graph algorithms (e.g., social network relationship traversal), trees, hash tables, chain tables, dynamic programming and involving concurrency, multithreading, operating systems, networking (TCP/IP), database principles (indexing, transactions, locking), concurrent programming, RPC frameworks and system design.
DE
Responsibilities:Build, maintain and optimize large-scale data pipelines (ETL/ELT), data warehouses/data lakes, ensure data quality, availability and liquidity, provide data support to data scientists and product teams
Interviews examine technical points: advanced data structures and algorithms, linear algebra, probability statistics, distributed file systems, distributed computing, SQL deep optimization. Data quality and monitoring, ML algorithm principles, model evaluation, model deployment and monitoring.
The Key Areas of Tech Interview
In order to excel in a Software Engineer interview at Twitter (or X), it is equally crucial to respond strategically to the pattern of programming questions. Based on common interview experiences and profile feedback, Twitter interviews are notoriously difficult forArrays,Strings,Trees respond in singing Graphs of basic traversals (e.g., DFS/BFS) has a clear focus. At the same time, as we discussed earlier, theStacks Related topics also featured heavily in Twitter interviews.
Unlike some companies with a heavy focus on complex algorithms, Twitter looks at programming models for theSimulation,Two Pointers as well as the basicHash Tables respond in singingLinked Lists It also has a high level of focus. While Dynamic Programming may also appear, it does not usually dominate the core or high level of difficulty as it does at some companies. This suggests that Twitter's programming interviews are as much about a candidate's mastery of core data structures and basic algorithms as they are about the ability to solve real-world problems and handle the details of the code.Twitter's programming interviews are as much about solid fundamentals as they are about the ability to efficiently utilize basic tools to solve real-world problems.
| Features | Percentage |
|---|---|
| Misc | 10.3% |
| Simulation | 5.2% |
| Two Pointers | 8.6% |
| Adv. Data Structure | 12.1% |
| Backtracking | 8.6% |
| Basic Data Structure and Algorithm | 13.8% |
| Binary Search | 5.2% |
| Heap | 12.1% |
| Graph | 3.4% |
| Dynamic Programing | 3.4% |
| Depth-First Search | 8.6% |
| Breadth-First Search | 8.6% |
Twitter's interview process is similar to a typical programming interview, but favors low to medium difficulty questions, especially data structure questions involving the stack. These questions usually require data to be managed in a Last-In, First-Out (LIFO) fashion, and are therefore relatively easy to understand and explain in an interview. Candidates may encounter common stack-related problems, such as bracket matching, expression evaluation, or implementing custom stack operations.
Overall, Twitter's programming challenges are typically less difficult and a friendlier experience for candidates compared to companies like FAANG (Facebook, Apple, Amazon, Netflix, Google). Additionally, Twitter's interview process often focuses on problem-solving skills and the ability to write clear, efficient code.
If you look at the percentage of difficulty of the questions, only 28% were easy questions, the percentage of moderately difficult questions was as high as 50%, and the remaining 22% were high-difficulty interview questions.
Questions and Difficulty
| Common Interview Questions | Examining technical points | degree of difficulty or ease |
|---|---|---|
| Count of tweets per frequency | Advanced Data Structures, Basic DSA, Dichotomous Finding | medium difficulty |
| Minimal mutation | breadth-first search | medium difficulty |
| Find out how long a user has been active | Basic Data Structures and Algorithms | medium difficulty |
| Flat Nested List Iterator | depth-first search | medium difficulty |
| Best place to meet | Basic Data Structures and Algorithms | challenging |
| the Alien Dictionary | Breadth-first search, depth-first search, graphs | challenging |
| Insert Delete Get Random Number O(1) | Basic Data Structures and Algorithms | medium difficulty |
| Verify IP Address | Basic Data Structures and Algorithms | medium difficulty |
| Design Tweets | Basic data structures and algorithms, heap | medium difficulty |
| Counting the number of students in each faculty | Basic Data Structures and Algorithms | medium difficulty |
Twitter OA (online assessment)
Twitter's Online Programming Assessment (OA) is actually their first "technical handshake" with many applicants. Its main purpose, like an initial screening, is to quickly and efficiently assess whether a candidate has solid basic programming skills and problem-solving abilities before a formal one-on-one technical interview. It wants to see if you can read a problem, translate ideas quickly and efficiently into code that runs, and maintain a clear mind under some time pressure. It's a chance to show your basic skills and a crucial step in determining whether you'll make it to the next round - after all, it's an essential screening process in the face of a huge number of applications.
For us candidates, the most important thing to keep in mind when facing this session is to return to the basics. A solid grasp of common data structures and algorithms is a prerequisite, do more easy to moderately difficult programming practice questions, familiarize yourself with the feeling of completing the coding within the time limit. When you take the test, you must be calm, read the requirements carefully, understand all the boundary conditions, and after writing the code, even if there is no automatic test to help you, you must go through the test cases in your head or on the draft paper to check the logic. Time management is very important, don't get stuck on one question. Remember, OA is a platform to show your basic ability to "get the job done", and it is a knock on the door to more in-depth exchanges, so take it seriously and show your basic strengths to the full!
Front-end Development Engineer
- basic research project: Data structures and algorithms, system design, and problem solving skills.
- Additional technical points: JavaScript/TypeScript language depth, asynchronous programming, event loops, principles of front-end frameworks (React, Vue, etc.), componentized thinking, state management, DOM manipulation, how browsers work, rendering flow, front-end performance optimization, web request handling, front-end security, building toolchains.
- Interview Questions:
- Implement a generic event delegate function delegate(parent, selector, eventType, handler).
- Given a large tree data structure (simulating a DOM tree), how do you efficiently find all nodes that satisfy a certain condition (e.g., node attributes match)? (may involve tree traversal or a specific lookup algorithm)
- Design and implement a UI component (e.g. a rating star component) that can change responsively, taking into account its state management and event handling.
- How to optimize the first screen load speed and subsequent rendering performance of a slow loading single page application (SPA)? Please give specific strategies.
- Explain the Event Loop mechanism of the browser and give a code snippet containing setTimeout, Promise, async/await and analyze the order of their output.
Backend Development Engineer
- basic research project: Data structures and algorithms, system design, and problem solving skills.
- Additional technical points: Principles of Distributed Systems (CAP Theorem, Consistency Model, Service Discovery, Load Balancing), Multi-threading and Concurrent Programming, Database Theory (SQL/NoSQL, Indexing, Transactions, Locks), Caching Strategies, Message Queuing, API Design (RESTful, gRPC), High Availability and Scalability Design of Systems, Networking Protocol Fundamentals. In-depth understanding of specific backend languages and their ecologies.
- Interview Questions:
- Implementing a thread-safe producer-consumer model.
- The design of a highly concurrent short link service (e.g., URL Shortener) requires consideration of features such as generation, lookup, and statistics, and discusses its scalability.
- How to achieve efficient and consistent data updates in a distributed caching system? Discuss common cache-elimination strategies and applicable scenarios.
- Given a scenario where you need to deal with a large number of user relationships (followers, fans), how to design the storage structure and query API to support fast follow/unfollow operations and user feed stream generation?
- Explain the principles, advantages and disadvantages of distributed transactions (e.g., 2PC or 3PC) and how to deal with eventual consistency across services in a microservices architecture.
Mobile Engineer
- basic research project: Data structures and algorithms, system design, and problem solving skills.
- Additional technical points: SDK and API depth for specific mobile platforms (iOS/Android), UI development (UIKit/SwiftUI or Android UI components), application architecture patterns (MVC, MVVM, MVI, etc.), mobile performance optimization (memory, CPU, power, network), multi-threading and asynchronous processing (GCD, Coroutines, etc.). ), data persistence, network request processing, offline function implementation, platform features (push notification, background tasks).
- Interview Questions:
- Implement a function that determines if a linked table has a ring and finds the start node of the ring (generic DSA question, often used to examine the basics).
- Designing an image loading and caching module within a mobile application requires consideration of memory caching, disk caching, network request optimization, and concurrency handling.
- In iOS/Android, how do you perform a time-consuming task (e.g. data synchronization) in the background while ensuring that the user experience is not compromised when the app is in the foreground? Please describe the technique you use.
- Explain the life cycle of a View/ViewController or Activity/Fragment in iOS/Android and explain what actions should be performed at different life cycle stages.
- How can I optimize the sliding smoothness and memory usage of a list view containing a large number of complex list items, such as a Twitter feed?
DE
- basic research project: Data structures and algorithms, system design, and problem solving skills.
- Additional technical points: SQL and its optimization, data modeling (paradigms, star/snowflake schema), ETL/ELT pipeline design, batch and stream processing principles (e.g. Spark, Flink, Kafka Streams), distributed file systems (HDFS, etc.), data warehouse/data lake concepts, data quality and validation, workflow orchestration (e.g. Airflow), large-scale performance optimization for data processing.
- Examples of typical interview questions:
- Write a SQL query that calculates the number of times each user has been active each day for the past 7 days, and displays 0 if a day is inactive.
- Design a data pipeline that is capable of capturing, transmitting, processing and ultimately storing user's clickstream events in the application from the front-end in real-time or near-real-time into a data warehouse for analysis.
- Explain the differences and scenarios for batch processing (e.g., Spark Batch) and stream processing (e.g., Spark Streaming or Flink) and how they differ in terms of fault tolerance.
- How to design a scalable data warehouse schema to store historical user behavior data? Consider query efficiency and storage costs.
- You are given a large dataset of billions of user records, each containing a user ID and access timestamp. How can you calculate the Top 100 most visited users with limited memory? (may involve distributed processing or chunked processing + Top K algorithm)
Behavior Questions
Behavioral questions are an important part of the examination in software engineer interviews, designed to understand the way you handle real-world work situations, collaborate with your team, and respond to technical challenges.
Interviewers often use situational questions to assess your project management and problem solving skills. For example, you may be askedDescribe an experience managing a challenging project under tight deadlines.. Answers should detail how you specifically manage your time, prioritize tasks, collaborate with team members, and highlight your ability to solve problems and stay productive under pressure. Another common question isTalk about a project where you introduced a new technology or a new framework, these types of questions want to hear how you learned to adapt, collaborate with your team, and successfully integrate new technologies and their impact on project outcomes. If asked aboutCan you give an example of an experience dealing with conflict within a development team, you need to discuss the communication strategies adopted, showing how leadership and empathy can be used to understand different points of view and reach consensus or compromise.
Teamwork is another key point of examination. You may be asked toDescribe an experience working with a team to solve a complex problem and how to ensure effective communication and collaboration. At this point, the focus should be on how you facilitated open communication and collaboration, mentioning the tools or methods used and how these efforts contributed to the success of the project. When askedExamples of having helped mediate disputes within a development teamWhen doing so, explain the mediation techniques you used, such as active listening, and how you remained neutral, facilitated a productive discussion, and ultimately reached a solution that was respectful of differing viewpoints and in line with the project's goals. Given the high demand for real-time performance at Twitter (now X), the interviewer might also askOnce you're in a Twitter-like environment where you have to implement a feature on a tight deadline, to see how well you perform under high pressure and your insistence on quality.
There will also be behavioral issues that are more focused on technical scenarios. For exampleDescribe an experience where you optimized a feature to improve scalability under a tight deadline, you can discuss specific optimization strategies (e.g. caching, indexing) and how to manage time and communication to ensure project success.Provide an example of a tricky bug you've encountered in a past project and how it was resolved., is to get a sense of your debugging mindset, analytical approach, and problem-solving tenacity. Given Twitter/X's emphasis on user experience and rapid deployment, you might also be askedHow to deal with pushing new features that may harm the user experience, at which point explaining how to find a balance between innovation and user satisfaction, such as iterating and gathering feedback through A/B testing or feature switches, would be a good direction to answer.
Interview Prep
Preparing for an interview for an engineer position at Twitter (or X) really requires some hard preparation and training on your part. It's not just a battle of skills, but also an opportunity to showcase your overall qualities and potential.
First, you have to go back to the core technical foundation - data structures and algorithms (DSA), which is like the foundation of a building, and is fundamental to support you in solving all programming problems. In particular, you have to take the time to become proficient in the common structures of arrays, strings, hash tables, chained lists, trees, and graphs, as well as basic algorithms such as Depth-First Search (DFS), Breadth-First search (BFS) and other basic algorithms. Recall that we said earlier that Twitter focuses more on low to medium difficulty questions, and stack-related questions are especially important, so you don't need to go into those extremely complex problems right off the bat, but rather, you need to familiarize yourself with these basic and medium difficulty questions first, to develop the "muscle memory" to quickly recognize problem patterns and write clear, efficient code. This is the foundation for passing the OA and subsequent programming rounds.
The ability to code is only the first step. For non-junior positions, System Design is another biggie. It's about how you can build a scalable, highly available system that can handle massive amounts of users and data, just like Twitter itself. In preparation, think about common system components (database, caching, message queues, load balancing, etc.) and their trade-offs and trade-offs in large-scale applications. Meanwhile, behavioral interviews are equally critical; they're not about technology, they're about you as a person - how you collaborate with the team, handle conflict, deal with stress and challenges, and whether you fit into the team culture. Use STAR rules (Situation, Task, Action, Result) to sort out your past project experiences, prepare a few stories that show your problem solving, leadership, teamwork and learning from failure, express yourself sincerely, and let the interviewer see a real, flesh and blood you.
On the day of the interview, in addition to your knowledge base, your on-the-spot performance and mindset are crucial. When you get a programming problem, don't rush to write the code, communicate with the interviewer first to make sure you fully understand the problem, clarify any ambiguities, and even ask about boundary conditions. When thinking about the solution, "think out loud" and tell the interviewer your thoughts step by step, even if it's a violent solution at first, so that you can understand it and then optimize it together. When writing code, try to be clear and neat, and don't forget to walk through the test cases after writing, checking for logical errors and boundary conditions. Don't be silent when you get stuck, but be honest and ask the interviewer for hints. Keep a positive and open attitude throughout the process, and show your problem-solving process rather than just pursuing the final answer. Finally, remember to prepare a few high-quality questions to ask the interviewer. This shows your interest and is a great opportunity to learn more about the team and the company. Remember, an interview is a two-way communication process, show your ability and enthusiasm, and also get a feel for whether they are the kind of partner you want to join!
